I've owned three BD packs in the eight years that I've been climbing and this one is by far my least favorite. But first i'll start with the features I liked about it:
Tons of space in this thing, easily fit a double rack, waters bottles and layers no problem. Side Zippers are a great features, get to the crag and dump your gear out in a flash.
Now the aspects that aren't so nice...
Granted I used the pack for guiding this summer for roughly 90 days but I expected it to hold up a little better than it did. Within a month the draw string for the lid snapped and I had to pain painstakingly thread a new piece of cord through, as well as the stitching on the shoulders blew out within two months. The removable brain is a good idea but without the correct amount of stuff in the pack the brain wont a line correctly and it just sits funny on the pack.
Just my two cents but I defiantly think a better design with more durable material is in order. Great for someone who is taking this to the crag maybe once every weekend, but for a person who is taking this out on multi day outings or guiding plan on buying at least three per year with the way that it holds up.